408 valve train noise

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mustangdart

mustangdart

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I have a 408 magnum, 12-1, E-85, .560 lift hydraulic roller, magnum R/T heads, all valve train from hughes. The problem is @ 2500 rpm it sounds like the lifters collapse, @ idle sounds like a sewing machine. I have tried adjusting the valves warm, cold, running, 0 preload, 1/4 preload/ 1/2 preload, 3/4 preload. No matter what I still have noise. I have noticed when I turn the engine over any lifter on high lobe will bleed off immediately, any rocker on off lobe will be loose (no preload). Is this typical of hydraulic cams?
 
Sounds like you may have that lifter bore issue that exposes the oilng hole, from being counter sunk too deep from the factory, maybe not..maybe just springs.

I was gonna say detonation, but then you said you found the lifter to bleed down instantly..
 
Did you assemble it? The lifters can go in two ways... One way they can be noisey. The right way they aren't. The oil hole faces the camshaft bore on Magnum/LA rollers if you're running factory type lifters. Factory roller shave a paint daub denoting the hole location on the top so it's easy to tell. Non OEM replacements do not.
 
You can tell pretty easily about the lifter bore thing. If the top of the lifter bores are chamfered, then chances are that's what's goin on. Not all blocks were machined like that, but a lot were.
 
few days ago i read an article from hughes website where they said the magnum hydraulic roller lifters need .080" preload - check the thread on your adjusters to know how many turns you need to preload them correctly. Let us know if it works!

Michael
 
pulled the intake this morning to see if I had installed lifters wrong and check on lifter bore. lifters are installed correctly and lifter oil hole is not exposed. I also just read the Hughes instructions that recommend .080 to .120 preload on lifters. I spoke with there tech guy when I assembled and he said max performance was with as little preload as possible. I have built many hydraulic flat tappet engines and always run 1/8 to 1/4 turn and they worked super. Just didn't make sense to even try that much preload. Gonna have to try. BUT when I inspected lifters there seemed to be a lot of scuffing on the bottom 1/2 of lifter that looked like too much angel pressure was on them also a couple of the lifter lobes showed signs of wear from the rollers at the start of the ramp. nose looked fine and base circle was fine just at the start of the lift.
 
Do you have roller rockers? The Hughes roller rockers I have sound kind of like a sewing machine at idle. If the sound is from the rockers, then it's normal. If it's coming from the lifters, I couldn't tell you because I have no experience with roller lifters. The wear on the lifters doesn't sound good. Did you run a burnishing ball through the lifter bores?
 
had block work done buy a small machine shop...I never asked to have lifter bores done so probably not. I have hughes roller rockers, sewing machine sound is ok, that TAP TAP TAP @ 2500 drives me nuts! I think I'm gonna put it back together and when it blows sell it for scrap. The geometry of a small block mopar is just stupid, why didn't they have the lifters so the push rod comes straight off them instead of such a BIG angle?
 
I don't know about the lifters collapsing at RPM thing, but my Magnum is noisy at idle. Had the same thing on hydraulic roller fords with aggressive camshafts. The grinders say the lobes on the cam just make them noisy.

My lifters bleed down very fast too. Its annoying but it hasn't hurt anything so far. I haven't checked my lifter bores for partial chamfering....WTF Mopar? They did that on Magnum blocks?

Also, that seems like a lot of lift for the R/T heads. Have you checked your clearances on retainer/guide and coil bind?

Good luck

Steve
 
heads were machined for the hughes 1111 springs. Just did some checking .080 is two turns of preload...2.75 turns bottoms out lifter.
 
Oh.

I don't know if Magnums have that problem - maybe they do, and I'll be checking when I put my Victor on in a couple of weeks.

The lifter bores in a standard 360 are shorter than a Magnum, so that *might* only be a worry for blocks that are retrofitting hydraulic rollers.

Certainly, when I called hughes about my noisy valvetrain, spoke to Dave, he didn't mention lifter bores. He said "Call comp, its their cam that's making all the noise" LOL.

Steve
 
this is so frustrating. I try to set preload, one lifter will collapse and then another will not. Looks like I have to take each one out and take it apart. maybe some are dirty and that is the problem.
 
Having any trouble with #7? That's where my bleed down is the worst. Also, when I run up the oil with a drill its the last one to oil.

And: doesn't seem like they oil at max lift at all, which is weird.
 
I would like to thank everyone for your input!!!! As it turns out the problem IS the preload. I just set the lifters with almost 2 turns of preload and it is MUCH quieter. Some times you have to stop doing what always worked in the past and read the instructions.
 
sounds good! so now i really know how much preload my lifters will need if the engine is finished....thanks for investigation:thumrigh:

Michael
 
I run .040-.050 on them and they are usually quiet. From the wear you have, the lifter bores may not be machined into the block well. It's common on Mopars. You also may have a lot of bore wear, which will mean more oil pressure bled past, and more preload required. You don't want more than .002" oil clearance on the lifter to lifter bores or you may have issues like that. If it gets loud again you may want to consider a solid roller and have the bores bushed.
 
I had to go with a small base circle cam on my retrofit hydraulic roller to keep the lifter oil groove from being exposed at max lift. I ran my oil pump with a drill and turn the engine over by hand to verify no excessive oil bleed off. The hydraulic rollers in a SB mopar also make the geometry worse and in a lot of cases you will need to enlarge the push rod holes in the heads for clearance.
 
with the pushrods not being straight up and down seems like side to side clearance on the rockers would be important, one of those things I think people don't really pay attention to, that might be part of the reason the sewing machine sound is accepted.
 
the pushrod thing is a problem that I already encountered. had to enlarge the holes in the heads because the pushrods were hitting. I bought these heads used and the old rocker arms and pushrods were junk because they would hit the side of the head and as the cam lifted higher they would come out of the socket of the rocker arm just enough to cause a rocking effect on the socket and make them egg shaped. as you can imagine it did the same to the pushrods.
 
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